Process of bridge construction.



ill-. LI'JTEN. momma n? BRIDGE.' CONSTRUCTION.

AEPLIUATIUN FILED JUNE 27, 1913.

lmtentsd Mar. 7. .E914A @firm/119g D. B. LUTEN.

Pnocms of' Hmmm CGNSTEUO'MON.

APPLICATION IILED HUNT. 53T; 1916.

LQ-@@jgg u Patented Mli'. lili, 3.13142 r y cig/1 von for rendesse r srars Damiana. Lumen, or INnIaNaPoLIs, namens.`

., i PQCES @1T BRJTDGE CONSTRUCTION.

all. whom t may concern, tile it' known that I, DaNmL Lures, a

' C'i'tin of the United States,-residing at lnebeate o t. Indiana, have invented a new and useful' Process of Bridge Constructitai, ot

which the following is a speciticatioii.

i'n the modern development of railroads, there iscontinually arising; the necessity' ot increasing' the number of tracks, as from a siirgle ltrack to a double track and from a double, track to four tracks. As grade crossings have already been largely abol'- ished' and are being further abolished each yeargand are in .many instances replaced by viaductsv orbridges crossings the tracks, increasixlig the number tracks becomes very expensive if all .the viaducts or bridges crossing the railroads must be' demolished and flargerviaducts or. bridges substituted for them. And yet it is imprglrctieable to build the viaducts or bridgesv of suliicient span nntlally for possible future increase 1n thenuifnber of tracks, l

y 'Thel object of my invention is to provide 4a process of bridge construct-ion and ahridge structure whereby a bridge or viaduct, especially a concrete bridge or viaduct may be bnilt initialiy with a given span,'ns across two railroad tracks, and may later be given an `enlarged span, as across four railroad tracks, without involvirfg the destruction of thexentire bridge or via uct.

f The accompanying drawings illustrate my i? invention.

jligure 1 is an elevation of the initial conx dition ot' a bridge involving my invention,

the ,bridge here spanning two railroad tracks; Fig. 2 a View showing a transition condi* tion as thelspan of the bridge of Fig. 1 is being 'widened ,to cover four tracks, one on each side o1 the original two; Fig. 3 is a view/'showing a transition condition as the of the bridge of Fig. 1 is being widened to cover four tracks, the two additional t'racks'being on the same side of the original two tracks; Fig. 4t is an elevation of the completed bridge after it has passed through the` transition condition and spans the four tracks.; Fig. 5 is an elevation fof the bridge in` ,itsV initial i condition, showing the general i arrangement of reinforcing or tension members; and. Fig; 6 is an elevation of the comy plete or widened bridge, showing the General arrasa;lenient'or' the reinforcing or Sneiticatvn vf Letters Patent Patented Mar. 10, 1914.. Application filed June 27, i913. Serial No. 776,024.

lor string members 16, the latter formingl the Hoor of the bridge and subtendine the arch 'termed the members l5, and the mcn'ibers 15 am, ttl being joined by uprights 17. Preferably suitable reinforcing or 'tension members 18 are embedded in and oxtcnd along the curved members 15. The ends of the members 18 are conveniently anchored to tension members 19 embedded in and extending along the chord or string member 16 into the end of the members 15. Other tension inon'ibcrs 20 may be embedded in the uprights 17, and are preferably suitably anchored in the members 15 and 1G, as by being connected to the tension members 1S and 19. The bow-string girder is selfcontained as to thrusts, exerting no end thrusts on its supports.

ln the. arrangement shown, the girder spans two railroad tracks 21 and 22, the piers 11 being located at the outer sides of such tracks. The bridge is now as shown in Fig. 1. Now let it be supposed that it is desired to add two more tracks 23 and 24. to the two tracks already comprising the rail-V road, and that these two additional tracks are located ou opposite sides of the tracks 21y and 22 already in use. In order to make this addition, the span of the bridge must be increased. '.Fherefore, two `new piers 31 are built ontheouter sides of and beyond the piers 11, and from springings 32 on the inner sides of those piers are extended arch sections 33 which joint to and form continuations of the members 15 of the bow-string girder 10. From the outer side of each pier 31 .is extended an arch segment 43d, the opposite endof which rests on, and may be anchored to, an abutment 35. The piers 31 `and the arch segments 33 and 34 are cast'to include the pillars 13 which intersect them, the latter being roughened if desired at the remmer omnes.

place olf intersection to allow permanent 35. The parts, 31 33, 34, 35 and 36 are also conveniently of concrete. The piers 31 are provided with reinforcing members 37, the. arch segments' 33 with reinforcing members 38, and the arch segments 34 with reinforcing members 39, the ends of the members 37 and 38remote from their supporting pier 31 being connected by tie-rods or tension members 40 which are conveniently embedded in the approaches 12 .and approach extensions 36 and extend into and are permanently an- .chored in the ends of the members 33 and in the transition condition shown in Fig. 2.'

After the concrete has hardened, the embankment is excavated to the line 41, the piers 11 are'removed, and the parts of the pillars v 13 below the arch segments 33 and f 34 are cut o and removed. Then the addii invisible in the 'completed bridge shown in 'tional tracks 23 and 24 are laid under the "bridge, which now appears as shown in Fig. 4. The joint 42l between the ends of the `members 15 ofthe bow-string girder and the arch segment 33 is inconspicuous or even Fig. 4.

If in increasing -the-number of tracks of the'railwa'y, the increase is unsymmetrical, as because the two additional tracks 23 and 24 are both to be added to the same side of the-tracks already in use, as indicated in Fig. 3, "the process of widening the span is only slightly different. In that case, the starting point as before is with the bridge in the form shown in Fig. 1. The bow-string girder lO'is supported onfalse-work, the piersll are removed,a`nd the bow-string girder is rolled in its entirety on the falsework to a position over the center of the four-.tracks (two new and two old) which the road is to have. It is usually necessary to demolish part or all of the approach on that side of the bridge toward which the' bow-string girder is moved, though the other approach 12 may usually be left intact. Then proper excavation of the embankment is made to the line 4:5, to accommodate the two new tracks 23"an.d 24', the piers 31 and 32 are built, the arch segments 33 and 34 are constructed on these piers, retaining as much of the original concrete as is in proper place (practically the ent-ire approach' 12 andl the upper parts of the pillars 13 at the right hand side of the bridge), then approach extensions 36 are added'to complete the approaches, and then the falsework is removed, leaving the bridge in the same condition as above described, or as shown in Fig. at.

I claim as my invention: 1. The process of constructing a bridge or a viaduct, comprising constructing a bowstring girder of concrete, reinforcing suoli girder so that it is self-contained as I\to lthrusts, supporting such bow-string -girdgr on piers under its ends, constructing pii-s farther apart than the `length 'of such bowstring girder, building arch segments from Isuch last named vpiers and of sufficient length to extend under the ends ofthe bow-string girder, and removing the'fir'st named piers and allowing the bow-string girder to rest on said arch segments.

2. The process of constructing a bridge or a viaduct, comprising construct-ing a bow-y string girder, supporting such bow-string girder-on piers under its ends,l constructing piers farther apart than the length of such bow-string girder, building 'arch segments from such last named piersand of suiiicient length to extend under the ends of the bow-string girder, and removing the first named piers and allowing the bow-string girder to rest on said arch segments.

3. The process of constructing 4a bridge or a viaduct, comprising constructing a bowstring girder of concrete, reinforcing such girder so that it' is self-contained as to thrusts,- constructing piers farther apart than the length ofsuch bow-string girder, building arch' segments from such piers and of sufficient length to extend under the ends of the bow-string girder, and allowingthe bow-string girder to rest on said arch segments.

4. The process of constructing a bridge or a viaduct, comprising constructing a bow-v string girder, constructing piers farther apart than the length of such bow-string girder, buildin arch segments from such piers and of su cient length to extend under the ends of the bowstring girder, and allowing the bow-string girder to rest on said arch segments. v

5. The process of constructing a bridge or a viaduct, comprising constructing a bowstring' girder, constructing piers farther apart than the length of such bow-string girder, building lateral projections from such piers and of suflicient length to extend under the ends of the bow-string girder, and allowing the bow-string girder to rest on said lateral projections. 7

6. The process of constructing a bridge or a'viaduct, comprising constructing a bowstring girder, supporting such bow-string girder on piers under its ends, constructing piers farther apart than the length of such bow-string girder, building lateral projections from such last named piers and of sufficient length to extend under the ends of the bow-string girder, and removing'the iro first named piers and allowing the bowstring girder to rest on said lateral projections.

7. The process of constructing a bridge or a viaduct, comprising constructing a bowstring girder, cons tructingpiers'farther apart than the length of such bow-string gir-der, building lateral projections from such piers and ot sullicient length to extend under the ends of the boustring girder, and albinring cross member by piers under its ends, constructing piers farther aparty than the length of such cross member, and building a lateral extension from each of said last named piers toward the' other suiliciently far so that the adjacent ends of such extensions are no farther apart than the length of such cross member, making each ot' such extensions self-contained with its supporting pier, and removing the first named piers and allowing the cross member to rest on said extensions.

9. The process of constructing a bridge and a viaduct, comprising constructing a self-contained cross member and supporting such cross member by piers under its ends.

constructing piers farther apart than the length of such cross member, and building a lateral extension from each ot said last named piers toward the other sntlieiently far so that the adjacent ends ot' such extensions are no farther apart than the length of such cross member, and removing the first named piers and allowing the cross member to rest on stud extensions.

In Witness whereof, I have hereunto set my hand at Indianapolis, Indiana, this twentieth day of June, A. D. one thousand nine hundred and thirteen.

DANIEL B. LUTEN. Witnesses FRAN I; A. Fama), G. B. Senter. 

